Studies in pediatric blood disorders provide an important paradigm for understanding the fundamental mechanisms regulating hematopoiesis and stem cell biology. Unlike adult hematologic disorders, many pediatric diseases result from intrinsic genetic defects that control blood cell development or function. Very little is understod about the molecular pathogenesis of many of the hematologic diseases in children. We plan to develop an innovative, multidisciplinary training program in pediatric nonmalignant hematology and stem cell biology with investigators who have unique expertise and can foster team science. Therefore, we propose a training program that integrates a variety of disciplines and expertise, including molecular and cellular hematopoiesis, alternative organism models, stem cell transplantation, novel technologies in proteomics/genomics, and bioinformatics. Currently, there is no program at Stanford University that supports the training of MD, MD/PhD, or PhD fellows to study Pediatric Nonmalignant Hematology and Stem Cell Biology. Given the declining number of translational and basic researchers in this area, a training program in nonmalignant hematology and stem cell biology will be critical to advance the field. In this application, we seek funding for two MD, MD/PhD, or PhD postdoctoral fellows per year for two years. Trainees will have the opportunity to develop research in one of the 23-faculty member's laboratories. Co-mentors and team science will be highly encouraged. Trainees will be selected from a pool of approximately 80 internal postdoctoral fellow candidates in addition to external candidates based on their academic potential, career goals, and research achievements. The second year of funding will depend on progress. Trainees will be required to participate in multidisciplinary journal clubs, hematology and stem cell biology lectures, clinic conferences, and joint research seminars. Trainees will also take a required course on Pediatric Nonmalignant Hematology and Stem Cell Biology (Pathology 290) with lectures given by the faculty mentors in the training program. Pediatric Hematology/Oncology MD or MD/PhD fellows will meet with their Scholarship Oversight Committees every 6 months to monitor progress and productivity. Trainees will present their work at national meetings, such as ASH, Keystone, and FASEB meetings. We hope to utilize the strengths of Stanford University to develop research collaborations in pediatric nonmalignant hematology and stem cell biology, including the breadth and depth of investigators across many disciplines, to train future leaders in the field.